Plotting instrument.



No. 747,522. PATENTED DEG.22,1903.

L. E. WILKES.

PLOTTING INSTRUMENT. 1

APPLICATION FILED SEPT. 30, 1901. H0 IODEL.

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UNITE STATESv Patented December 22, 1903,

PATENT OFFICE.

PLOTTING INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 747,522, dated December 22, 1 3- Application filed eptember 30, 19(11- $erial No, 77,164. (No model.)

To all whom it may concern:

Be it known that I, LINCOLN E; WILKES, a citizen of the United States, and a resident of Hillsboro, Washington county, in the State of Oregon, have invented a new and useful Plotting Instrument, of which the following is a specification, reference being had to the accompanying drawings as constituting a part thereof.

My invention has for its object to obtain a drawing instrument which will facilitate the work of laying off boundary-lines and courses in accordance with field-notes; and the same consists of a jointed four sided frame or jointedly-connected sections of two four-sided jointed frames, the distance between the joints of opposite members being equal, so

that the four sides of each frame-section will represent a parallelogram. One, end of such frame constitutes a base and is adapted to be rigidly secured'to the drafting table or board, and the other extremity is provided with a jointedly attached and extending ruler, along the edges of which the courses are to be drawn and the required length set off by the graduated edge thereof. The free end of said frame is movable over any part of the paper on which the plot or figure is being developed, and said ruler is adjustable to any convenient angle of deflection, and each of the angles of deflection to which said ruler may be adjusted will at any part of the drafting area accurately correspond with the common meridian or base, from which the courses are determined. Besides the advantages afforded by my plotting instrument, as will be hereinafter shown, the same is particularly serviceable for making plots on a large scale.

The details of the construction of my invention are as shown in the drawings, in which- Figure 1 shows a plan of my said plotting instrument. Fig. 2 is a diagrammatic representation of my invention modified to a simple form of construction, and Fig. 3 shows a modification in the construction of the parts at the free end'of the frame carrying the protractor and adjustable blade or ruler.

Referring to the letters as designating the parts specified in the description of my invention hereinafter given and describing,

first, Fig. 1, A is a bar which is adapted to be rigidly secured to the drafting table or board and represents the fixed base from which the plot or figure is to be developed. As shown in the drawing Fig. 1, said basebar is provided at its extremities a a with perforations in which to receive screws to secure said bar in place. To the central. portion of such base-bar at e and f are jointedly attached bars I) c of equal length, and to the extremities g h of said bars I) c is jointedly attached the bar (1, having a right-angle extension or member (1. To the points gm of said member 01 are jointedly attached the arms qlj of equal length, andto the extremities Z n of said arms ij is jointedly attached a bar is. The member 61 and bar k are of equal length, and the bar 01 is of a length corresponding to the distance between the joints 6 and f. In other words, the four sides of each section of the jointed frame-as, for example, A d b c and d k j 1lrepresent a true parallelogram.

By observation of the instrument described it will be seen that the bar A functionates as a fixed base and that the jointed connection of the bar is therewith is such that the latter will constantly maintain its relative position with respect to such base-bar A no matter to what point of the surface of the paper the bar It may be moved, and consequently when the ruler 10 has been set to a true perpendicular position it will correctly represent a meridian at any point of the drafting-surface, and the angle to which such ruler is deflected will represent the angle of deflection from such meridian, and a line or course corref sponding to such angle of deflection may be accurately produced by marking along the edge of the ruler on any part of the drafting area, the length of the line being determined at the same time by the graduatlons along the edges of the ruler. For a greaterconvenience the bar la of the instrument shown in Fig. 1 is provided with a pivoted protractor 0 and a fixed Vernier q, to which to adjust the graduated edge of the protractor, and the ruler p in this case is a prolonged radius of the circle of such protractor. In Fig. 3 the protractor 0' is rigidly attached to the bar k and has pivoted to the center of its" circle an arm 10 moving over the protractor, and to such arm is attached a ruler 19 the arm 19 being provided with an index or Vernier g at its extremity. In either case the joint of the ruler is such that the latter after having been properly adjusted may be fixed in place by means of a thumb-nut r. The provision of a protractor is optional, and when myinstrumentis not provided with a protractor a separate protractor may be properly secured at any, convenient point within the sweep of the ruler, the ruler set to the desired angle, as ascertained from said separate protractor, then clamped,and finally carried to the point from which course the line is to be drawn.

When my instrument is constructed without a protractor, its use is limited to producinga line at one point corresponding with the position or direction of a line at another point and operates in this respect likeaparallel ruler; but my ruler possesses far greater advantages than the parallel ruler, for it maybe conveniently used for transferring a line from one point to another over a large drafting area, and, furthermore, the zeropoint on the scale edge of the ruler may always be brought to the beginning of the line, so that the latter may be simultaneously measured and ruled. In Fig. 2 the right-angle extension or member d (shown in Fig. 1) is omitted, and the extremities of the side bars 1' j corresponding to the bars 1' j of Fig. 1 are directly jointed to the ends h g of the end bar d. This is a mere simplification of my instrument, not affecting its described operation.

Having fully described my invention, now what I claim, and desire to secure by Letters Patent, is

A plotting instrument consisting of a basebar adapted to be fixedly secured; a jointed frame comprising members b, c and d, the latter having an integral right-angle extension d; a second jointed frame comprising members 2,3, 70, of which the members 'i and j are jointed at g and m, respectively, of the main frame; a radially-adjustable ruler, carried by the free end of the second jointed frame; and means for indicating the degree of the angle to which such ruler has been adjusted.

In testimony whereof I have hereunto affixed my signature, in the presence of two witnesses, this lth day of September, 1901.

LINCOLN E. WILKES.

Witnesses:

T. J. GEISLER, E. M. HOWATSON. 

